Monitoring and conservation of the largest loggerhead turtle (Caretta caretta) nesting population in Africa: successes and challenges.

[EN] The Republic of Cape Verde is situated about 500 km off the coast of Senegal, West Africa. The islands of Sal, Boa Vista and Maio constitute the Eastern group and harbour the most important nesting beaches for loggerhead turtles in the Archipelago. During 1998-2004 nesting seasons, fieldwork has been focused on the eastern beaches of Boa Vista and, occasionally, in other beaches of Boa Vista and in the islands of Maio, Sal and Santa Luzia. The main study area includes a total extension of 3.1 km of suitable nesting beaches. All through these years, a tagging program has been carried out, alongside recording of biological data and monitoring of nests.

Natural colonization of loggerhead turtle eggs by the pathogenic fungus Fusarium oxysporum

[EN] Sea turtle nests are exposed to different environmental risks that may affect their hatching success. Human exploitation, predation by wild or domestic animals, nest flooding or severe beach erosion or accession are common causes of egg mortality. However, there is very little information about the impact of microorganisms on turtle eggs. We analyzed loggerhead turtle eggs from Boavista Island (Republic of Cabo Verde) which were incubated under different environmental conditions in order to evaluate the presence and impact of fungus. We have isolated Fusarium oxysporum from dead and live eggs after three days of incubation.

The international importance of the archipelago of Cape Verde for marine turtles, in particular the loggerhead turtle Caretta caretta

[ES] The shores of Cape Verde hosts one of the most important nesting populations of the loggerhead turtle Caretta caretta in the world, as well as important feeding grounds for hawksbill Eretmochelys imbricata and green turtles Chelonia mydas. In the past few years, a number of scientific studies have demonstrated the relevance of the waters and beaches of this archipelago for the conservation of these endangered marine megavertebrates. This article aims to bring together the most relevant scientific information published on the subject so far. In addition, we will provide an overview of the current situation of sea turtles in Cape Verde, their conservation status and their importance in an international context.

Injuries observed in nesting females of loggerhead turtles on Boavista island (Cabo Verde Archipelago)

[EN] Different kinds of physical anomalies are frequently observed in any sea turtle breeding population. Nesting beaches are an excellent place to study the injuries and defects that occur in adult females. The archipelago of Cape Verde is situated about 500 km of Senegal, West Africa. Boavista is the eastern most island and may constitute the most important nesting area for the loggerhead turtle in the archipelago. The studies conducted from 1998 to 2004 indicate that Cape Verde might account for one of the most important loggerheads populations in the eastern Atlantic. The nesting females in Boavista were surveyed during the 2004 season, in order to (1) know the health status of the population (2) determine the effects of physical anomalies on nesting behaviour and (3) determine the possible origin of the injuries observed.

Injuries observed in nesting females of loggerhead turtles on Boavista island (Cabo Verde Archipelago)

[EN] Different kinds of physical anomalies are frequently observed in any sea turtle breeding population. Nesting beaches are an excellent place to study the injuries and defects that occur in adult females. The archipelago of Cape Verde is situated about 500 km of Senegal, West Africa. Boavista is the eastern most island and may constitute the most important nesting area for the loggerhead turtle in the archipelago. The studies conducted from 1998 to 2004 indicate that Cape Verde might account for one of the most important loggerheads populations in the eastern Atlantic. The nesting females in Boavista were surveyed during the 2004 season, in order to (1) know the health status of the population (2) determine the effects of physical anomalies on nesting behaviour and (3) determine the possible origin of the injuries observed.

The coast of Cape Verde hosts the third largest loggerhead nesting population in the world

[EN] Extensive sea turtle nesting monitoring has been conducted in several islands of the Archipelago of Cape Verde during the past years. The loggerhead turtle is the only species that nests in these islands though green and hawksbill turtle juveniles are very often found feeding around their coasts. Around 90% of loggerhead nests are deposited in the island of Boavista on approximately 50 km of white sandy beaches. This is one of the less populated islands with more inaccessible beaches, as all villages are far from the main nesting areas. Another 9% of nests are equally distributed among the islands of Sal, Maio and San Nicolau and the remaining 1% of nests are found among the other six major islands and several islets of the archipelago.

Tendencias espacio-temporales en las capturas accidentales de tortuga boba (Caretta caretta) en la costa catalana entre los años 2000 y 2009

Se describen las tendencias en las capturas accidentales de tortuga boba (Caretta caretta) a lo largo de la costa catalana (Mediterráneo occidental) a partir de los datos del Centro de Recuperación de Animales Marinos de Cataluña. En Girona, la provincia más septentrional y base de la fracción mayor de la flota pesquera de Cataluña, es donde se produce un mayor número de capturas accidentales de esta especie. La mayoría de estas capturas se dan en los meses de verano, coincidiendo con el mayor esfuerzo pesquero del año. La gran mayoría de los individuos son capturados vivos, siendo el palangre el aparejo que provoca más de la mitad de las capturas incidentales en esta región. ABSTRACT: Trends in the loggerhead turtle (Caretta caretta) captured along the Catalonian coasts (Western Mediterranean) are described using data collected by the Marine Animal Rescue Centre of Catalonia. Girona, the most northerly province and base of the greater fraction of the fishing fleet of Catalonia, is the area where the greater part of loggerhead turtle was captured, particularly during the summer, coinciding with the higher fishing effort season. The majority of individuals were caught alive, and the longline appeared to be the fishing gear that causes more than half of the incidental captures in this region

Modelling the niche for a marine vertebrate: A case study incorporating behavioural plasticity, proximate threats and climate change

[EN] The integration of satellite telemetry, remotely sensed environmental data, and habitat/environmental modelling has provided for a growing understanding of spatial and temporal ecology of species of conservation concern. The Republic of Cape Verde comprises the only substantial rookery for the loggerhead turtle Caretta caretta in the eastern Atlantic. A size related dichotomy in adult foraging patterns has previously been revealed for adult sea turtles from this population with a proportion of adults foraging neritically, whilst the majority forage oceanically. Here we describe observed habitat use and employ ecological niche modelling to identify suitable foraging habitats for animals utilising these two distinct behavioural strategies. We also investigate how these predicted habitat niches may alter under the influence of climate change induced oceanic temperature rises.

Evaluation of male breeding population inferred from paternity analyses in the Cape Verde islands

[EN] Because of the extensive migrations of marine turtles through the ocean, many aspects of their biology have been unknown for a long time. However, much information has been recently gained from genetic studies and population monitoring of female turtles at their nesting sites. In contrast, still very little is known on the genetic diversity, population structure and dispersal patterns of the male breeding population, mainly because of the difficulty of capturing and monitoring them at sea. The aim of this study is to assess the genetic patterns of the male breeding population of the loggerhead turtle, Caretta caretta, using a non invasive approach and compare them to the female breeding population.

Fusarium solani is responsible for mass mortalities in nests of loggerhead sea turtle, Caretta caretta, in Boavista, Cape Verde

[EN] The fungus Fusarium solani (Mart.) Saccardo (1881) was found to be the cause of infections in the eggs of the sea turtle species Caretta caretta in Boavista Island, Cape Verde. Egg shells with early and severe symptoms of infection, as well as diseased embryos were sampled from infected nests. Twenty-five isolates with similar morphological characteristics were obtained. Their ITS rRNA gene sequences were similar to the GenBank sequences corresponding to F. solani and their maximum identity ranged from 95% to 100%.

Population structure and conservation implications for the loggerhead sea turtle of the Cape Verde Islands

[EN] The Cape Verde Islands harbour the second largest nesting aggregation of the globally endangered loggerhead sea turtle in the Atlantic. To characterize the unknown genetic structure, connectivity, and demographic history of this population, we sequenced a segment of the mitochondrial (mt) DNA control region (380 bp, n = 186) and genotyped 12 microsatellite loci (n = 128) in females nesting at three islands of Cape Verde. No genetic differentiation in either haplotype or allele frequencies was found among the islands (mtDNA FST = 0. 001, P > 0. 02; nDNA FST = 0. 001, P > 0. 126). However, population pairwise comparisons of the mtDNA data revealed significant differences between Cape Verde and all previously sequenced Atlantic and Mediterranean rookeries (FST = 0. 745; P < 0. 000).

Twelve new polymorphic microsatellite markers from the loggerhead sea turtle (Caretta caretta) and cross-species amplification on other marine turtle species

[EN] We describe 12 new polymorphic dinucleotide microsatellite loci and multiplex Polymerase Chain Reaction conditions from the loggerhead sea turtle Caretta caretta. Levels of polymorphism were assessed in 50 individuals from the nesting population of the Cape Verde Islands.